1. Field of the Invention
The present invention relates to pedicle screw instrumentation, and more particularly to a lumbar spine pedicle screw guide for improving the accuracy of pedicle screw insertion and the safety of instrumentation used in pedicles of the lumbar vertebrae.
2. Description of the Related Art
Pedicle screw instrumentation is the main method used to achieve instrumented fusion between the vertebrae in thoracic and lumbar spine regions. The process typically requires insertion of pedicle screws with accuracy and precision in order to avoid injury to the near-by nerve roots and achieve adequate fixation. Various techniques have been developed to improve the accuracy of pedicle screw placement. Such techniques, however, often require complex or expensive equipment in order to achieve a high rate of accuracy (e.g., greater than 90%). Consequently, free-hand techniques, having lower success rates and accuracy (e.g., 68%-80%), are the most commonly used techniques.
Pedicle guides used with free-hand techniques can sometimes incorporate parts that must be inserted under the bone, which is not recommended because of the risks in neurologic injury and not recommended for patients with spinal canal narrowing (i.e., stenosis). Additionally, such pedicle guides do not facilitate procedures on two pedicles of the same vertebra at the same device position, thereby resulting in increased x-ray usage and potential variability in pedicle screw placement. Such pedicle guides also fail to address instrumentation of multiple vertebrae, despite the fact that spinal fusion typically requires instrumentation of two or more adjacent vertebrae.
Thus, a lumbar spine pedicle screw guide solving the aforementioned problems is desired.